rust: update the minimum version of Rust...
rust: update the minimum version of Rust
Debian Bullseye has just been released, and it carries `rustc 1.48.0`.
This actually implies a regression that we can't really do anything about in
`rhg`. See
https://github.com/rust-lang/rust/issues/88825. In short, closed (or
bad) standard file descriptors are reopened silently with no way of telling by
the Rust runtime before `main` is executed. This means that closed fds are not
forwarded to the subprocess we run in case of fallback. This is a bit sad, but
probably not something worth worrying too much about.
Differential Revision:
https://phab.mercurial-scm.org/D11341
